Head lamps should last as long as possible in operation. There are however other requirements that must be met. Cost of the lamp is one consideration. The lamp must produce the necessary amount of light to properly illuminate the road. The light must be spread according to prescribed patterns, so the illuminating source structure must work with existing reflectors and lenses to reproduce the proper patterns. Head lamps require a substantial amount of power and this demand may influence the overall system requirement. To lower the overall cost of the electrical system, lower power requirements for vehicle headlamps is a desirable result. Currently, daylight running headlamps are becoming a recognized safety feature. Running headlamps constantly does not result on average in more lamp failures per lamp hour, but does result on average in more lamp failures per vehicle running hour. There is then a need for increased vehicle headlamp life, without substantially effecting lamp cost, light output or distribution, or vehicle power system